Electric fire-alarm.



PATENTED APR. 23, 1907.

W. H. H. EVERETT. ELECTRIC FIRE ALARM.

APPLICATION FILED SEPT. 22, 1904.

WILLIAM HENRY HARISON EVERETT, OF NEWTON FALLS, OHIO.

ELECTRIC FlRE-ALARNI.

Specification of Letters Patent.

Patented April 23, 1907.

Application filed September 22, 1904. Serial No. 225,54A.

To all whmn it nuty concern:

Be it known that 1, WILLIAM HENRY HARP SON EVERETT, a citizen of the United States, residing at Newton Falls, in the county of Trumbull and State of Ohio, have invented a new and useful Improvement in Electric Fire-Alarms, of which the following is a specification.

This invention relates to an automatic fire alarm in which the contacting plates are held apart through the medium of a glass bulb which is filled with a liquid readily eX- pansible under a comparatively low temperature; the bursting of the bulb permitting the contact plates to be forced together by means of a spring.

The object of the invention is to avoid the use of a metallic flux, the melting of which as in the case of plugs and fuse wires often results in the molten metal flowing in such a manner as to cause a short circuit or to interfere with the proper working of the alarm, and the furtliier object is a device of this kind which can be depended upon to send in an alarm when the temperature reaches a certain point which is not the case with alarms using the ordinary fuse wires or plugs as the melting temperature of the said fuses vary with the composition and proportion of the alloy of which they are composed and is usually from two to three times that of the temperature of boiling water.

My invention also consists in the novel features of construction and combination of parts, hereinafter set forth, particularly pointed out in the claims and shown in the accompanying drawings, in which,

Figure 1 is a front elevation of my device. Fig. 2 is a side elevation of the device. Fig. 3 is an end view of the device as seen from below. Fig. 4 is a detail sectional view through the bulb.

In these drawings, A represents the wooden base which may be secured to a wall by means of suitable screws, and which, adjacent its lower end, carries a transverse cross piece A, vertically slotted at A and having a horizontal bore A intersecting the vertical slot A The face of the board A, forming the rear side of the slot A has a concavity A formed therein. A glass tube B closed at its upper end is carried by the front face of the board A and at its lower end terminates in a bulb B which rests in the slot and in the concavity A the bulb being of thinner glass than the remainder of the tube. The bulb and tube are filled with an expansible liquid as shown at B and the tube is held in place by means of staples B and a transverse cleat C arranged at its upper end upon the base A.

Projecting forwardly from the cross piece A are two horizontal, cylindrical bars D threaded at their outer ends and connected by a bracket D. A rod E is loosely supported adjacent its outer end in an aperture formed in the bracket D and the inner end of the rod E bears 011 the bulb B. A segmental metal plate E is carried by the rod E and is suitably perforated and adapted to slide on the bars D. This plateE has straight end portions E which form the movable contact plates of the device. A collar E is fixed on the rod E and a spring F is coiled around the rod E and bears at its outer end on the bracket D and at its inner end on the segmental plate E holding the same against the collar E Screws H are carried by the cross piece A and when the plate E is forced inward by the spring F, the end portions will contact with the heads of the said screws H. Binding posts H of the usual construction are mounted upon the cross piece A and from these binding posts lead the circuit wires H Connecting wires H extend from the binding posts to the screws H and are held snugly under the heads of the said screws in the usual manner. Suitable nuts G are employed to hold the bracket D in position and permit the adjustment of the said bracket in order to regulate the tension upon the spring F.

It will be obvious that as long as the glass bulb B remains intact the rod E will be held outward and the contact plates E spaced from the heads of the screws H, but as soon as the rise of temperature expands the liquid in the bulb and tube sufficiently to burst the bulb, the rod E can move inward and the spring F will force the segment E also inward holding the contact plates E against the screws 11 thus completing the circuit through the segment E between the wires H.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is z A device of the kind described comprising contact points spaced apart, parallel bars, a bracket adjustable on and connecting said bars, a rod having an end portion loosely supported by said bracket, segmental WILLIAM 111mm HMIISUN livlanu'lil. plate slidably mounted on the bars, said YVitnesses:

plate being carried by the rod, a spring bear- 1 LiasLiE R LIBL'E) ing at one end 011 the bracket and at the SAM ()vm'r'i.

other end on the plate, a glass bull) resting against the inner end 01' the rod, an and expansihle fluid in the glass bull). 

